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| HowTo Linux Zone | Linux Zone Home | E-Mail Me | The Linux Electronic Mail HOWTO Guylhem Aznar <guylhem at oeil.qc.ca>
v2.2, January 1999
This document describes the setup, care and feeding of Electronic Mail
(e-mail) under Linux. You need to read this if you plan to communi&SHY;
cate locally or to remote sites via electronic mail. You probably do
*not* need to read this document if don't exchange electronic mail
with other users on your system or with other sites.
______________________________________________________________________
Table of Contents
1. Introduction, copyright and standard disclaimer
1.1 Email and spamming
1.2 Goals
1.3 New versions
1.4 Feedback
1.5 Copyright
1.6 Limited warranty
2. Other sources of information
2.1 USENET
2.2 Mailing Lists
2.3 Other documents from LDP
2.4 Books
3. Requirements
3.1 Hardware
3.2 Software
4. Qmail v1.03
4.1 Getting qmail
4.2 Uncompressing sources
4.3 Preparing compilation
4.4 Configuring qmail
4.4.1 defaultdomain, me, plusdomain
4.4.2 locals, rcpthosts
4.4.3 virtualdomains
4.5 Testing qmail
4.6 Removing your other MTA
4.7 That's all, folks !
5. Smail v3.1
5.1 Configuring smail
5.2 "config" file
5.3 "directors" file
5.4 "fidopaths" file
5.5 "routers" file
5.6 "transports" file
5.7 "maps/" directory
5.8 Other good examples
5.9 Restarting inetd
5.10 Smail with smtp
6. OUTDATED SECTION : Sendmail+IDA
6.1 Source installation
6.2 The sendmail.m4 file
6.3 Defining a local mailer
6.4 The sendmail+IDA dbm tables
6.5 So which entries are really required?
6.6 Sendmail 8.x
6.7 A sample 8.7.x mc file
6.8 Sendmail v8 tidbits
6.9 Local Delivery Agents
7. POP mail
7.1 History
7.2 Getting mail
7.3 Sending mail
7.4 Reading mail
7.5 Testing
7.6 Using
8. Mail "user agents"
8.1 Mutt
8.2 Elm
8.3 Mailx
8.4 Other user agents
9. Acknowledgements
______________________________________________________________________
1. Introduction, copyright and standard disclaimer
1.1. Email and spamming
First, convert all "at" in Emails address to "@".
It's simple for humans, but not for bots searching the web to spam ;
therefore it's enough to protect generous contributors from being
spammed !
1.2. Goals
The intent of this document is to answer some of the questions and
comments that appear to meet the definition of "frequently asked
questions" about e-mail software under Linux in general and the
version in the Linux Debian and RedHat distributions in particular.
1.3. New versions
New versions of this document will be periodically posted to
comp.os.linux.announce, comp.answers and mail.answers. They will also
be added to the various anonymous ftp sites who archive such
information including sunsite.unc.edu:/pub/Linux/docs/HOWTO.
In addition, you should be generally able to find this document on the
Linux WorldWideWeb home page at http://sunsite.unc.edu/mdw/linux.html.
1.4. Feedback
I am interested in any feedback, positive or negative, regarding the
content of this document via e-mail. Definitely contact me if you
find errors or obvious omissions.
I read, but do not necessarily respond to, all e-mail I receive.
Requests for enhancements will be considered and acted upon based on
that day's combination of available time, merit of the request and
daily blood pressure :-)
Flames will quietly go to /dev/null so don't bother.
Feedback concerning the actual format of the document should go to the
HOWTO coordinator : Greg Hankins (gregh at sunsite.unc.edu).
1.5. Copyright
The Mail-HOWTO is copyrighted (c) 1998 Guylhem Aznar. Distributed
under LDP copyright license. If you have questions, please contact
Greg Hankins, the Linux HOWTO coordinator, at gregh at
sunsite.unc.edu.
1.6. Limited warranty
Of course, I disavow any potential liability for the contents of this
document. Use of the concepts, examples, and/or other content of this
document is entirely at your own risk.
2. Other sources of information
2.1. USENET
There is nothing "special" about configuring and running mail software
under Linux (any more). Accordingly, you almost certainly do *NOT*
want to be posting generic mail-related questions to the
comp.os.linux.* newsgroups.
Don't post in comp.os.linux hierarchy unless it's really linux
specific, for example : "Which options was Debian 1.2 sendmail
compiled with ?" or "RedHat 5.0 smail crashes when I run it".
Let me repeat that.
There is virtually no reason to post anything mail-related in the
comp.os.linux hierarchy any more. There are existing newsgroups in
the comp.mail.* hierarchy to handle *ALL* your questions.
IF YOU POST TO COMP.OS.LINUX.* FOR NON-LINUX-SPECIFIC QUESTIONS, YOU
ARE LOOKING IN THE WRONG PLACE FOR HELP. THE MAIL EXPERTS HANG OUT IN
THE PLACES INDICATED ABOVE AND GENERALLY DO NOT RUN LINUX.
POSTING TO THE LINUX HIERARCHY FOR NON-LINUX-SPECIFIC QUESTIONS WASTES
YOUR TIME AND EVERYONE ELSE'S AND IT FREQUENTLY DELAYS YOUR GETTING
THE ANSWER TO YOUR QUESTION.
GOOD PLACES are :
comp.mail.elm the ELM mail system.
comp.mail.mh The Rand Message Handling system.
comp.mail.mime Multipurpose Internet Mail Extensions.
comp.mail.misc General discussions about computer mail.
comp.mail.multi-media Multimedia Mail.
comp.mail.mush The Mail User's Shell (MUSH).
comp.mail.sendmail the BSD sendmail agent.
comp.mail.smail the smail mail agent.
comp.mail.uucp Mail in the uucp environment.
2.2. Mailing Lists
There are many sendmail, smail and qmail mailing lists.
You can find addresses in /usr/doc/the_one_you_have_chosen.
2.3. Other documents from LDP
There is plenty of excellent material provided in the other Linux
HOWTO documents and from the Linux DOC project.
In particular, you might want to take a look at the following:
· on your own computer in /usr/doc/ :-)
· the Linux Networking Administrators' Guide
· the Serial Communications HOWTO
· the Ethernet HOWTO
· the UUCP HOWTO if you're fed via UUCP
2.4. Books
The following is a non-inclusive set of books that will help:
· "Managing UUCP and USENET" from O'Reilly and Associates is in my
opinion the best book out there for figuring out the programs and
protocols involved in being a USENET site.
· "Unix Communications" from The Waite Group contains a nice
description of all the pieces (and more) and how they fit together.
· "Sendmail" from O'Reilly and Associates looks to be the definitive
reference on sendmail-v8 and sendmail+IDA. It's a "must have" for
anybody hoping to make sense out of sendmail without bleeding in
the process.
· "The Internet Complete Reference" from Osborne is a fine reference
book that explains the various services available on Internet and
is a great source for information on news, mail and various other
Internet resources.
· "The Linux Networking Administrators' Guide" from Olaf Kirch of the
Linux Documentation Project is available on the net and is also
published by (at least) O'Reilly and SSC.
It makes a fine one-stop shopping to learn about everything you
ever imagined you'd need to know about Unix networking.
3. Requirements
3.1. Hardware
There are no specific hardware requirements for mail under Linux.
You'll need some sort of 'transport' software to connect to remote
systems, which means either TCP/IP or uucp.
This could mean that you need a modem or ethernet card, depending on
your setup. In most cases, you'll want the fastest modem you can
afford, i.e. V90 57 600 bps currently. In general, you want to have a
16550 UART on your serial board or built into your modem to handle
speeds of above 9600 baud.
If you don't know what that last sentence means, please consult the
comp.dcom.modems group or the various fine modem and serial
communications FAQs and periodic postings on USENET.
3.2. Software
Well, the problem is here. Which mail software will you choose ?
There is currently qmail, smail, vmail and sendmail.
Each has its own features, but the better compromise is qmail, for
high security (even is vmail is more secure), high speed (even is
smail is faster for local uses) and ease of configuration.
Of course, feel free to choose any mail software, informations
provided here shall only help you in your choice.
Sendmail can be nice for many sites with complicated options, but I
think its configuration is too hard for beginners while it is not very
secure or very fast, so there is only a really outdated sendmail
section in this HOWTO.
If you know what you're doing, choose sendmail (and you shouldn't be
reading this HOWTO !); otherwise I generally recommend qmail.
4. Qmail v1.03
Secured, fast and easy to use, this is my preferred MTA (mail
transport agent).
Currently, no distribution comes with qmail, so we will focus on
compiling and installing qmail, since this is the only tricky part :
configuration is really straightforward.
4.1. Getting qmail
Go to www.qmail.org to download latest version.
4.2. Uncompressing sources
Then decompress it running :
mv qmail.tar.gz /usr/local/src
cd /usr/local/src ; tar -zxvf qmail.tar.gz
If you find a bz2 version (new and better compression format), just
replace tar by :
bunzip2 qmail.tar.bz2
tar -xvf qmail.tar
4.3. Preparing compilation
Now enter qmail dir to check configuration defaults :
cd qmail; more conf-*
You shouldn't need to change any default, but you can for example
specify an alternate installation dir or better compilation flags.
Now run :
mkdir /var/qmail
to create target dir.
If you haven't installed a Debian distribution, you'll need to add
qmail own users : qmail's high security depends on that.
Nobody will be able to break your whole mail system or gain root
access since qmail is divided into modules running each under their
own UID.
So run :
# groupadd nofiles
# useradd -g nofiles -d /var/qmail/alias alias
# useradd -g nofiles -d /var/qmail qmaild
# useradd -g nofiles -d /var/qmail qmaill
# useradd -g nofiles -d /var/qmail qmailp
# groupadd qmail
# useradd -g qmail -d /var/qmail qmailq
# useradd -g qmail -d /var/qmail qmailr
# useradd -g qmail -d /var/qmail qmails
or hand-edit /etc/passwd and /etc/group to add these users by yourself
: for example you can respectively add :
qmail:*:2107:
nofiles:*:2108:
&
alias:*:7790:2108::/var/qmail/alias:/bin/true
qmaild:*:7791:2108::/var/qmail:/bin/true
qmaill:*:7792:2108::/var/qmail:/bin/true
qmailp:*:7793:2108::/var/qmail:/bin/true
qmailq:*:7794:2107::/var/qmail:/bin/true
qmailr:*:7795:2107::/var/qmail:/bin/true
qmails:*:7796:2107::/var/qmail:/bin/true
Now you can run
make setup check
to check your configuration, then :
./config
to configure qmail.
Now you must install some aliases, since /etc/alias is not used by
qmail unless you compile and install some optional package.
Here's my setup :
File : ".qmail-MAILER-DAEMON"
&postmaster
File : ".qmail-bin"
&root
File : ".qmail-daemon"
&root
File : ".qmail-decode"
&root
File : ".qmail-dumper"
&root
File : ".qmail-games"
&root
File : ".qmail-ingres"
&root
File : ".qmail-mailer-daemon"
&postmaster
File : ".qmail-manager"
&root
File : ".qmail-news"
&root
File : ".qmail-nobody"
&root
File : ".qmail-operator"
&root
File : ".qmail-postmaster"
&root
File : ".qmail-root"
&guylhem
File : ".qmail-system"
&root
File : ".qmail-toor"
&root
File : ".qmail-uucp"
&root
File : ".qmail-uucp-default"
|preline -dr /usr/bin/uux - -r -gC -a"${SENDER:-MAILER-DAEMON}" lm!rmail "($DEFAULT@$HOST)"
You need to create each of these file in ~alias, replacing &guylhem in
.qmail-root by your own login to get root mail.
ATTENTION UUCP USERS !
DO NOT TRUST QMAIL FAQ FOR UUCP, USE MY .qmail-uucp-default INSTEAD !
ELSE YOU WILL NOT BE ABLE TO SEND ANY MAIL BY YOUR UUCP CONNEXION !
Now you'll need to decide in which format your users will get their
mail.
Here's my suggestion :
· For NFS mounted home dirs, use MAILDIR format with a patch for
local mail readers (patchs are available on www.qmail.org)
· If no patch is available, prefer MAILFILE format : any mail reader
can read a file containing mail, people will only need to create an
alias (for bash) or a setenv (for csh) for their mail reader
· Avoid /var/spool/mail/$USER format, too unsecure
To fix default format, read each file in /var/qmail/boot then copy the
one you best like to /var/qmail/rc.
home or proc are safe choices, but prefer home for security reasons.
4.4. Configuring qmail
In /var/qmail/control, edit :
4.4.1. defaultdomain, me, plusdomain
· me is you local FQDN (full qualified domain name), for example on
my machine it is barberouge.linux.lmm.com
· defaultdomain will be added to any host name without dots,
including defaulthost, for example you can set it to localnetwork
so any mail sent to joe@hisbox will be completed to be sent to
joe@hisbox.localnetwork instead
· plusdomain is the exception : is is added to any host name that
ends with a plus sign, including defaulthost (set in me) if it ends
with a plus sign.
These 3 examples shows you the power and ease of configuration of
qmail !
4.4.2. locals, rcpthosts
If you want to support virtual domain names, just put additional names
in these files.
Any mail you receive for these names will be handled locally.
The difference between locals and rcpthosts is the latter isn't
considered as a local alias, which is useful if you receive mail from
some free email address like yahoo.com or lemel.fr while you also send
mail to other users of these non local services, i.e. you don't want
to handle locally mail send to someone@yahoo.com !
4.4.3. virtualdomains
There can you specify defaut outgoing mode, for example :
#:alias-uucp
if you don't want to send outgoing mail by uucp but by smtp (default)
or
:alias-ucp
if you send your outgoing mail by uucp.
4.5. Testing qmail
Now it is configured, try :
sh -cf '/var/qmail/rc &'
to launch qmail (it won't interfere with your local MTA), then :
echo to: mylogin | /var/qmail/bin/qmail-inject
You should receive this mail in the format you've chosen in
/var/qmail/boot/.
4.6. Removing your other MTA
If this test was successful, just kill your previous MTA :
killall -STOP daemon_name ; if any children are running, you should
killall -CONT their_name, wait, killall -STOP again, and repeat ad
nauseam.
If there aren't any children, killall -TERM and then killall -CONT.
Remove it (how you can do this depends on the distribution you
installed, for example rpm -e --nodeps on RedHat, Caldera and Suse, or
dpkg -r --force-depends on Debian) then run :
# ln -s /var/qmail/bin/sendmail /usr/lib/sendmail
# ln -s /var/qmail/bin/sendmail /usr/sbin/sendmail
Now set up qmail-smtpd in /etc/inetd.conf (all on one line):
smtp stream tcp nowait qmaild /var/qmail/bin/tcp-env tcp-env /var/qmail/bin/qmail-smtpd
If you are using a old non-SYSV-init distribution like redhat, just
add to your boot scripts :
sh -cf '/var/qmail/rc &'
Usually /etc/rc.local but your mileage may vary.
For actual SYSV-init compliant distributions (RedHat, Caldera, Suse,
Debian), add this script to /etc/init.d/ :
DEBIAN version :
#!/bin/sh
test -x /var/qmail/rc || exit 0
case "$1" in
start)
echo -n "Starting mta: "
sh -cf '/var/qmail/rc &'
echo "qmail."
;;
stop)
echo -n "Stopping mta: "
killall qmail-lspawn
echo "qmail."
;;
restart)
echo -n "Restarting mta: "
killall -HUP qmail-lspawn
killall -ALRM qmail-lspawn
echo "qmail."
;;
*)
echo "Usage: /etc/init.d/qmail {start|stop|restart}"
exit 1
esac
exit 0
REDHAT version :
#!/bin/sh
#
# qmail This shell script takes care of starting and stopping qmail.
#
# description: qmail is a Mail Transport Agent, which is the program \
# that moves mail from one machine to another.
# processname: qmail
# config: /var/qmail/control/
# Source function library.
. /etc/rc.d/init.d/functions
# Source networking configuration.
. /etc/sysconfig/network
export PATH=$PATH:/var/qmail/bin
# Check that networking is up.
[ ${NETWORKING} = "no" ] && exit 0
[ -f /usr/sbin/sendmail ] || exit 0
# See how we were called.
case "$1" in
start)
# Start daemons.
echo -n "Starting qmail: "
qmail-start '|preline procmail' splogger qmail &
touch /var/lock/subsys/qmail
echo
;;
stop)
# Stop daemons.
echo -n "Shutting down qmail: "
killproc qmail-lspawn
echo
rm -f /var/lock/subsys/qmail
;;
restart)
$0 stop
$0 start
;;
status)
status qmail
;;
*)
echo "Usage: qmail {start|stop|restart|status}"
exit 1
esac
exit 0
And make symlinks to each /etc/rcN.d/, for example :
ln -sf /etc/init.d/qmail /etc/rc1.d/K19qmail
If the first letter is K, you will kill qmail on this runlevel (1 for
single mode or 6 for boot), but if the first letter is S, you will
start qmail on this runlevel (each others runlevel).
· How to decide whether you should put a K or a S ? Do what the
majority of dæmons in this runlevel do !
· What number should you put after K or S ? The number next to your
network daemon.
RedHat, Caldera and Suze will use /etc/rc.d/ instead of plain /etc/
for Debian distribution, i.e. /etc/rc.d/rc1.d or /etc/rc.d/init.d for
example.
4.7. That's all, folks !
No need to reboot (remember, you're using linux, not some other cheap
OS !) for the modifications to take effect, just run :
killall inetd
init 1
To go to single user mode, then :
init 2
to go back to your default runlevel (indicated in /etc/inittab with
initdefault label).
You could also hand-start qmail script but "init" method will show you
if qmail script is well positioned, i.e. launched after network
scripts but before any program depend on email to warn you (like inn).
5. Smail v3.1
Smail3.1 seems to be a de-facto standard transport agent for uucp-only
sites and for some smtp sites. It's easy to configure, it compiles
without patching from the sources and it's fairly secure.
5.1. Configuring smail
Install smail binary from your distribution (I recommand you choose
this) or get smail sources and build smail. If you're building smail
from sources, you need to have the following in your os/linux file so
that 'sed' gives you shell scripts that work properly.
CASE_NO_NEWLINES=true
Once it's installed, config. files will certainly go in /etc/smail
(but your mileage may vary if you use old distributions); let's start
editing them !
5.2. "config" file
# From
smart_path=polux
smart_transport=uux
# To
hostname=barberouge
domains=linux.lmm.com
visible_name=barberouge.linux.lmm.com
uucp_name=barberouge.linux.lmm.com
# max_message_size=512k
# auth_domains=foo.bar
# more_hostnames=barberouge.polux.freenix.fr
Well, first, who is feeding you ? I'm fed by "polux" via uucp (i.e.
uux transport); naturally you need to change this file according to
your own situation. For example, you could by fed by
"bargw.bar.foobar.com" via "smtp", in that case you don't need a
transport file and can define "-transport_file " to indicate you don't
need one.
You can also use "postmaster_address = yourname", hide the network
topology in outgoing addresses (if you're a gateway) using
"visible_name", set which aliases address can also be used for the
email you receive, using "more_hostnames".
See smail documentation for more details or the examples in
/usr/doc/smail/examples to see if any match your situation.
5.3. "directors" file
# aliasinclude - expand ":include:filename" addresses produced by alias files
# This entry and the next one are pretty much boiler-plate. Reasons
# for making significant changes are few. The sole purpose of these
# is to match and expand addresses of the form:
# :include:pathname
# which may occur in alias files or mailing-list/forward files
# (produced by any director with a driver of forwardfile).
aliasinclude:
driver = aliasinclude, # use this special-case driver
nobody; # associate nobody user with addresses
# when mild permission violations
# are encountered
copysecure, # get permissions from alias director
copyowners, # get owners from alias director
# forwardinclude - expand ":include:filename" addrs produced by forward files
forwardinclude:
driver = forwardinclude, # use this special-case driver
nobody;
copysecure, # get perms from forwarding director
copyowners, # get owners from forwarding director
# aliases - search for alias expansions stored in a database
# This is the standard aliases file. It is used for generic things,
# like mapping root, postmaster, MAILER-DAEMON and uucp to site
# admins, creating some small system alias expansions, and such. In
# this site configuration, the aliases file is used mostly for
# machine-specific aliasing/forwarding information. Global forwarding
# information should be put in the "forward" database.
aliases:
driver=aliasfile, # general-purpose aliasing director
-nobody, # all addresses are associated
# with nobody by default, so setting
# this is not useful.
sender_okay, # don't remove sender from expansions
owner=owner-$user; # problems go to an owner address
file=/etc/aliases,
modemask=002, # should not be globally writable
optional, # ignore if file does not exist
proto=lsearch, # unsorted ASCII file
# forward - search for expansions stored in a forwarding database
# This is the subdomain-wide user forwarding database. Entries are
# maintained here for current or past users, to forward their mail to
# their preferred mail-reading machine. The forward database is
# shipped around the TCP/IP network as changes are made, to keep the
# network consistent.
#forward:
# driver = aliasfile, # general-purpose aliasing director
# -nobody, # all addresses are associated
# # with nobody by default, so setting
# # this is not useful.
# owner = real-$user; # problems go to an owner address
#
# file = /etc/forward,
# modemask = 002,
# proto = dbm, # use dbm(3X) library for access
# dotforward - expand .forward files in user home directories
# For users that have an entry in the "forward" database, a ".forward"
# file is only used if it is on the "home" machine, as identified in
# the forward database. If used, it is treated as a list of addresses
# to which mail should be delivered, rather than (or in addition to)
# the user identified in the local address.
dotforward:
driver = forwardfile, # general-purpose forwarding director
owner = postmaster, nobody, sender_okay;
file = ~/.forward, # .forward file in home directories
checkowner, # the user can own this file
owners = root, # or root can own the file
modemask = 002, # it should not be globally writable
caution = daemon:root, # don't run things as root or daemon
# be extra careful of remotely accessible home directories
unsecure = "~uucp:/tmp:/usr/tmp:/var/tmp"
# forwardto - expand a "Forward to " in user mailbox files
# This emulates the V6/V7/System-V forwarding mechanism which uses a
# line of forward addresses stored at the beginning of user mailbox files
# prefixed with the string "Forward to "
forwardto:
driver = forwardfile,
owner = postmaster, nobody, sender_okay;
file = /var/spool/mail/${lc:user}, # point at user mailbox files
forwardto, # enable "Forward to " function
checkowner, # the user can own this file
owners = root, # or root can own the file
modemask = 0002, # under System V, group mail can write
caution = daemon:root # don't run things as root or daemon
# user - match users on the local host with delivery to their mailboxes
user: driver = user; # driver to match usernames
transport = local # local transport goes to mailboxes
# real_user - match usernames when prefixed with the string "real-"
# This is useful for allowing an address which explicitly delivers to a
# user's mailbox file. For example, errors in a .forward file expansion
# could be delivered here, or forwarding loops between multiple machines
# can be resolved by using a real-username address. Also, users that
# wish to use mail as a means of transferring data to a machine that
# is not their "home" machine can mail to real-login-name@remote.host.
real_user:
driver = user;
transport = local,
prefix = "real-" # for example, match real-root
# lists - expand mailing lists stored in a list directory
# mailing lists can be created simply by creating a file in the
# /etc/smail/lists directory.
lists: driver = forwardfile,
caution, # flag all addresses with caution
nobody, # and then associate the nobody user
owner = owner-$user; # system V sites may wish to use
# o-$user, as owner-$user may be
# too long for a 14-char filename.
file = lists/${lc:user} # lists is under $smail_lib_dir
# owners - expand mailing lists stored in a list owner directory
# mailing lists owner lists can be created simply by creating a file
# in the /etc/smail/lists/owner directory. Mailing list owners
# are sent locally generated errors dealing with a mailing list of the
# same name. To create an owner list for a mailing list, create a
# file with the name of the list in /etc/smail/lists/owner. This
# will create a list address of owner-listname, as is used by the
# "lists" director above.
owners: driver = forwardfile,
caution, # flag all addresses with caution
nobody, # and then associate the nobody user
owner = postmaster; # system V sites may wish to use
# o-$user, as owner-$user may be
# too long for a 14-char filename.
prefix = "owner-",
file = lists/owner/${lc:user} # lists is under $smail_lib_dir
# request - expand mailing lists stored in a list request directory
# mailing lists request lists can be created simply by creating a file
# in the /etc/smail/lists/request directory. Request addresses
# are typically used as a standard address for queries about a mailing
# list. For example, requests for additions or deletions to a list
# will generally be sent to "list-request", which should be set up to
# forward to the appropriate person or persons.
request: driver = forwardfile,
caution, # flag all addresses with caution
nobody, # and then associate the nobody user
owner = postmaster; # system V sites may wish to use
# o-$user, as owner-$user may be
# too long for a 14-char filename.
suffix = "-request",
file = lists/request/${lc:user} # lists is under $smail_lib_dir
You shouldn't need to change anything here, only mailing list options
if you intend to run some using smail, or forwards options if, for
example, you want to disable forwarding.
5.4. "fidopaths" file
.f105.n324.z2.fidonet.org f105.n324.z2.fidonet.org!%s
.n324.z2.fidonet.org f105.n324.z2.fidonet.org!%s
.z2.fidonet.org f105.n324.z2.fidonet.org!%s
.fidonet.org f105.n324.z2.fidonet.org!%s
Create such a file only if you're using ifmail and FIDO.
5.5. "routers" file
# forces - force certain paths
# This database exists as a means of hardcoding the paths to various
# machines or domains. It is for use in creating temporary tweaks to
# the other routing databases. To change the database, edit the file
# maps/force.path and type "make" in the maps/ subdirectory.
forces:
driver = pathalias, # router to search paths file
method = /etc/smail/maps/table; # transports are in this file
file = forcepaths, # file containing force path info
proto = lsearch, # use the sorted path file
optional,
reopen # close when not being used
uucp_neighbors:
driver=uuname, # use a program which returns neighbors
transport=uux;
cmd="/usr/bin/uuname -a", # specifically, use the uuname program
# domain=uucp # strip ending ".uucp"
# smart_host - a partially specified smarthost director
# If the config file attribute smart_path is defined as a path from the
# local host to a remote host, then hostnames not matched otherwise will
# be sent off to the stated remote host. The config file attribute
# smart_transport can be used to specify a different transport.
# If the smart_path attribute is not defined, this router is ignored.
smart_host:
driver = smarthost, # special-case driver
transport = uux # by default deliver over UUCP
# path=phreak
# ifmail - to send mails to fidonet and vice versa
ifmail:
driver=pathalias,
transport=ifmail;
file=fidopaths,
proto=lsearch
You should only include ifmail chapter if you use ifmail for FIDO
mails. Note you can also change transport mode from "uux" (ie UUCP)
to, for example, "smtp" or even 'hardcode the paths to various
machines or domains' in "/etc/smail/maps/table".
This is useful if you want outgoing mail for your local network to be
delivered immediately, since there's no need for it to be routed to
your uucp connexion of your internet access.
5.6. "transports" file
# local - deliver mail to local users
# Tell smail to append directly to user mailbox files in the /var/spool/mail
# directory.
#local: driver = appendfile, # append message to a file
# -return_path, # include a Return-Path: field
# local, # use local forms for delivery
# from, # supply a From_ envelope line
# unix_from_hack; # insert > before From in body
#
# file = /var/spool/mail/${lc:user}, # use this location for Linux
# # Note, mail spool must be 1777
# file = ~/mailfile, # use this location for better security
# group = mail, # group to own file for System V
# mode = 0660, # under System V, group mail can access
# suffix = "\n", # append an extra newline
# append_as_user,
# This allows each user to have a ~/.procmailrc file to control filtering
# of mail and saving mail from mail lists in separate mailboxes if they wish.
local: +inet,
-uucp,
driver = pipe, # append message to a file
return_path, # include a Return-Path: field
local, # use local forms for delivery
from, # supply a From_ envelope line
unix_from_hack; # insert > before From in body
cmd = "/usr/bin/procmail", # use procmail for local delivery
parent_env, # environment info from parent addr
pipe_as_user, # use user-id associated with address
umask = 0022, # umask for child process
# -ignore_status, # exit status should be believed
# -ignore_write_errors, # retry on broken pipes
# pipe - deliver mail to shell commands
# This is used implicitly when smail encounters addresses which begin with
# a vertical bar character, such as "|/usr/lib/news/recnews talk.bizarre".
# The vertical bar is removed from the address before being given to the
# transport.
#pipe: driver = pipe, # pipe message to another program
# return_path, local, from, unix_from_hack;
#
# cmd = "/bin/sh -c $user", # send address to the Bourne Shell
# parent_env, # environment info from parent addr
# pipe_as_user, # use user-id associated with address
# umask = 0022, # umask for child process
# -log_output, # do not log stdout/stderr
# ignore_status, # exit status may be bogus, ignore it
# ignore_write_errors, # ignore broken pipes
# file - deliver mail to files
# This is used implicitly when smail encounters addresses which begin with
# a slash or squiggle character, such as "/usr/info/list_messages" or
# perhaps "~/Mail/inbox".
#file: driver = appendfile,
# return_path, local, from, unix_from_hack;
#
# file = $user, # file is taken from address
# append_as_user, # use user-id associated with address
# expand_user, # expand ~ and $ within address
# check_path,
# suffix = "\n",
# mode = 0644
# uux - deliver to the rmail program on a remote UUCP site
#
# As many as five recipient addresses will be delivered to the remote
# host in one UUCP transaction.
uux: driver = pipe,
-uucp,
inet,
# uucp, # use UUCP-style addressing forms
from, # supply a From_ envelope line
max_addrs = 5, # at most 5 addresses per invocation
max_chars = 200; # at most 200 chars of addresses
# the -r flag prevents immediate delivery, parentheses around the
# $user variable prevent special interpretation by uux.
cmd = "/usr/bin/uux - -r -g$grade $host!rmail $((${strip:user})$)",
# cmd="/usr/bin/uux - $host!rmail $(($user)$)",
ignore_write_errors, # ignore broken pipes
umask = 0022,
# pipe_as_sender,
# uux_one_addr - deliver mail over UUCP to a remote host that can take
# one address at a time.
# This is often necessary when delivering to a site running an unmodified
# version of 4.1BSD.
uux_one_addr:
driver = pipe,
uucp, # use UUCP-style addressing forms
from; # supply a From_ envelope line
# the -r flag prevents immediate delivery
cmd = "/usr/bin/uux - -r -g$grade $host!rmail (${strip:user})",
umask = 0022,
pipe_as_sender
queueonly:
driver = pipe; # send the message to a pipe
cmd = "/usr/lib/sendmail -Q -f $sender -bm $user",
# use getmail for local delivery
user=root, # execute getmail as "root"
group=mail, # execute getmail as "mail"
parent_env, # environment info from parent addr
-pipe_as_user, # use user-id associated with address
umask = 0007, # umask for child process
# to deliver the message. The smtp transport is included only if BSD
# networking exists.
# The uucp attribute can be specified for transfers within the UUCP
# zone. The inet attribute must be specified for transfers within the
# Internet.
# NOTE: This is hardly optimal, a backend should exist which can handle
# multiple messages per connection.
# ALSO: It may be necessary to restrict max_addrs to 100, as this is the
# lower limit SMTP requires an implementation to handle for one
# message.
smtp: driver=tcpsmtp,
inet, # if UUCP_ZONE is not defined
# uucp, # if UUCP_ZONE is defined
-max_addrs, -max_chars; # no limit on number of addresses
short_timeout=5m, # timeout for short operations
long_timeout=2h, # timeout for longer SMTP operations
service=smtp, # connect to this service port
# For internet use: uncomment the below 4 lines
use_bind, # resolve MX and multiple A records
defnames, # use standard domain searching
defer_no_connect, # try again if the nameserver is down
local_mx_okay, # fail an MX to the local host
ifmail:
from,received,max_addrs=5,max_chars=200,
driver=pipe;
pipe_as_sender,
cmd="/usr/local/bin/ifmail -x9 -r$host $((${strip:user})$)"
You should include an ifmail chapter only if you use ifmail for FIDO
mails. Apart from that, you shouldn't need to edit anything in this
file which defines transport agents (like uux, smtp ...) you can use
as parameters in other config. files.
Note I commented out some parts, like "pipes" or "file", to enhance
security.
5.7. "maps/" directory
It contains map and table files :
First, map file
#N foo.bar foo2.bar2
#S AT 486/RedHat Linux 1.2.13
#O organization
#C contact
#E administration (email)
#T phone
#P address
#R
#U hosts connected via uucp
#W created/edited by
#
hname polux
hname linux.eu.org
hname = polux
hname = polux.linux.eu.org
Once again, edit this file to match you situation (I'm fed by
polux.linux.eu.org).
Now table file
* uux
You can define different transports to different path, for exemple
"smtp" for the machines in your local network, "uux" (i.e. uucp) for
the rest of the world or vice-versa (I'm using uucp for any outgoing
mail, therefore I use "*" !).
5.8. Other good examples
The previous files are the one I currently use for my site, you
shouldn't encounter any problem using them as samples/basis for your
own files.
The following files are provided only as good exemples to configure
smail a different way.
#ident "@(#) transports,v 1.2 1990/10/24 05:20:46 tron Exp"
# See smail(5) for a complete description of the contents of this file.
# local - deliver mail to local users
#
# Tell smail to append directly to user mailbox files in the /usr/mail
# directory.
local: driver = appendfile, # append message to a file
return_path, # include a Return-Path: field
local, # use local forms for delivery
from, # supply a From_ envelope line
unix_from_hack; # insert > before From in body
file = /usr/mail/${lc:user}, # use this location for System V
group = mail, # group to own file for System V
mode = 0660, # under System V, group mail can access
suffix = "\n", # append an extra newline
append_as_user,
# pipe - deliver mail to shell commands
#
# This is used implicitly when smail encounters addresses which begin with
# a vertical bar character, such as "|/usr/lib/news/recnews talk.bizarre".
# The vertical bar is removed from the address before being given to the
# transport.
pipe: driver = pipe, # pipe message to another program
return_path, local, from, unix_from_hack;
cmd = "/bin/sh -c $user", # send address to the Bourne Shell
parent_env, # environment info from parent addr
pipe_as_user, # use user-id associated with address
umask = 0022, # umask for child process
-log_output, # do not log stdout/stderr
ignore_status, # exit status may be bogus, ignore it
ignore_write_errors, # ignore broken pipes
# file - deliver mail to files
#
# This is used implicitly when smail encounters addresses which begin with a
# slash or squiggle character, such as "/usr/info/list_messages" or perhaps
# "~/Mail/inbox".
file: driver = appendfile,
return_path, local, from, unix_from_hack;
file = $user, # file is taken from address
append_as_user, # use user-id associated with address
expand_user, # expand ~ and $ within address
suffix = "\n",
mode = 0644
# uux - deliver to the rmail program on a remote UUCP site
#
# As many as five recipient addresses will be delivered to the remote host in
# one UUCP transaction.
uux: driver = pipe,
uucp, # use UUCP-style addressing forms
from, # supply a From_ envelope line
max_addrs = 5, # at most 5 addresses per invocation
max_chars = 200; # at most 200 chars of addresses
# the -r flag prevents immediate delivery, parentheses around the
# $user variable prevent special interpretation by uux.
cmd = "/usr/bin/uux - -r -g$grade $host!rmail $((${strip:user})$)",
umask = 0022,
pipe_as_sender
# uux_one_addr - deliver mail over UUCP to a remote host that can take one
# address at a time.
#
# This is often necessary when delivering to a site running an unmodified
# version of 4.1BSD.
uux_one_addr:
driver = pipe,
uucp, # use UUCP-style addressing forms
from; # supply a From_ envelope line
# the -r flag prevents immediate delivery
cmd = "/usr/bin/uux - -r -g$grade $host!rmail (${strip:user})",
umask = 0022, pipe_as_sender
# demand - deliver to a remote rmail program, polling on demand
demand: driver = pipe,
uucp, from, max_addrs = 5, max_chars = 200;
# with no -r flag, try to contact remote site immediately
cmd = "/usr/bin/uux - -g$grade $host!rmail $(($user)$)",
umask = 0022, pipe_as_sender
# uusmtp - deliver to the rsmtp program on a remote UUCP site
#
# Deliver using a simple Batched SMTP protocol to the remote machine.
# This allows much more arbitrary addresses to be used. It also
# removes the limit on recipient addresses per invocation of uux.
uusmtp: driver = pipe,
bsmtp, # send batched SMTP commands
-max_addrs, # there is no limit on the number or
-max_chars; # total size of recipient addresses.
# supply -r to prevent immediate delivery, the recipient addresses
# are stored in the data sent to the standard input of rsmtp.
cmd = "/usr/bin/uux - -r -g$grade $host!rsmtp",
umask = 0022, pipe_as_sender
# demand_uusmtp - deliver to a remote rsmtp program, polling on demand
demand_uusmtp:
driver = pipe,
bsmtp, -max_addrs, -max_chars;
# with no -r flag, try to contact remote site immediately
cmd = "/usr/bin/uux - -g$grade $host!rsmtp",
umask = 0022, pipe_as_sender
# smtp - deliver using SMTP over TCP/IP
#
# Connect to a remote host using TCP/IP and initiate an SMTP conversation to
# deliver the message. The smtp transport is included only if BSD networking
# exists.
# NOTE: It may be necessary to restrict max_addrs to 100, as this is the
# lower limit SMTP requires an implementation to handle for one
# message.
smtp: driver = smtp,
-max_addrs,
-max_chars
#ident "@(#) table,v 1.2 1990/10/24 05:20:31 tron Exp"
# This file names the transports that are to be used in delivering
# to specific hosts from bargw.
#host transport
#-------- ---------
curdsgw demand_uusmtp # deliver using batched SMTP
oldbsd uux_one_addr # 4.1BSD sites cannot take more than one addr
sun demand # call sun when their is mail to send
* uux # for all others, poll at intervals
5.9. Restarting inetd
To run smail as a smtp daemon, add one of the following to
/etc/inetd.conf:
smtp stream tcp nowait root /usr/bin/smtpd smtpd
or:
smtp stream tcp nowait root /usr/sbin/tcpd /usr/sbin/in.smtpd
Outgoing mail gets sent automatically, when using elm.
5.10. Smail with smtp
Generally, ISPs use smtp, therefore you shouldn't have any problems
sending your mail. If your internet link is down when you send mail,
then the mail sits in "/var/spool/smail/input". When the link next
comes up, "runq" is run which causes the mail to be sent. However,
receiving mail is the problem since your provider has many clients to
look after, not only you !
Usually, you can retreive your mail via the POP protocol, see POP
section below.
6. OUTDATED SECTION : Sendmail+IDA
For big sites, sendmail is worth choosing, due to the "incredible ease
of use", (very relative feeling when you know qmail) but you must
decide which you want between sendmail+IDA and sendmail 8.x :
· If you use an old kernel (1.0) : sendmail+IDA
· If you use a not so old kernel (1.2) : sendmail+IDA and source code
editing
· Recent kernel (2.0) will choose sendmail 8.x
Remember, linux newbies or people concerned by security / ease of
configuration should rather try using smail or qmail, which are easier
to use and safer.
6.1. Source installation
If your distribution doesn't provide you with a ready-to-install
sendmail package (.rpm for RedHat, Caldera and Suse, .deb for Debian)
just download the sources and run :
· cd / ; tar -zxvf sendmail5.67b+IDA1.5.tpz
· cd to /usr/local/lib/mail/CF and copy the sample.m4 local.m4 file
to "yourhostname.m4".
Edit out the distributed hostname, aliases, smarthost and put in the
correct one for your site. The default file is for a uucp-only site
who has domainized headers and who talks to a smart host. Then "make
yourhostname.cf" and move the resulting file to /etc/sendmail.cf
· if you are uucp-only, you do *NOT* need to create any of the tables
mentioned in the README.linux file.
You'll just have to touch the files so that the Makefile works. Just
edit the .m4 file, make sendmail.cf and start testing it.
· if you're uucp-only and you talk to sites in addition to your
"smart-host", you'll need to add uucpxtable entries for each (or
mail to them will also go through the smart host) and run dbm
against the revised uucpxtable.
· If you run Rich Braun's original binary distribution of 5.67a,
you'll need to freeze the configuration if you change your .cf file
with "/usr/lib/sendmail -bz" to make the changes take effect.
You should also update your version to at least 5.67b since there is a
nasty security hole in 5.67a and earlier. Another nice thing is that
if you have mail.debug set and you run syslogd, your incoming and
outgoing mail messages will get logged. See the "/etc/syslog.conf"
file for details.
The sources for sendmail+IDA can be found at vixen.cso.uiuc.edu ; they
require no patching to run under Linux if you're running something
like a kernel of 1.00.
If you're running a kernel > 1.1.50, you get the fun of reversing most
of the Linux-specific patches that are now in the vanilla sources. (I
*did* told you this sendmail was only for old kernels :-)
It's extremely obvious where this needs to be done : just type "make"
and when it blows up, go to that line in the sources and comment out
the Linux-specific code that's in there.
If you're going to run sendmail+IDA, I strongly recommend you go to
the sendmail5.67b+IDA1.5 version since all required Linux-specific
patches are now in the vanilla sources and several security holes have
been plugged that WERE (!!!) in the older version you may have grabbed
or built before about December 1st, 1993.
Now linux kernel is 2.0, you should use sendmail 8.x insted of
sendmail+IDA, but I told you'd better choose sendmail 8.x :-)
6.2. The sendmail.m4 file
Sendmail+IDA requires you to set up a sendmail.m4 file rather than
editing the sendmail.cffile directly. The nice thing about this is
that it is simple to set up mail configurations that are extremely
difficult (if not totally impossible for most people to set up
correctly) in smail or traditional sendmail.
The sendmail.m4 file that corresponds to the above smail example looks
like the following:
dnl #------------------ SAMPLE SENDMAIL.M4 FILE ------------------
dnl #
dnl # (the string 'dnl' is the m4 equivalent of commenting out a line)
dnl #
dnl # you generally don't want to override LIBDIR from the compiled in paths
dnl #define(LIBDIR,/usr/local/lib/mail)dnl # where all support files go
define(LOCAL_MAILER_DEF, mailers.linux)dnl # mailer for local delivery
define(POSTMASTERBOUNCE)dnl # postmaster gets bounces
define(PSEUDODOMAINS, BITNET UUCP)dnl # don't try DNS on these
dnl #
dnl #-------------------------------------------------------------
dnl #
dnl # names we're known by
define(PSEUDONYMS, myhostname.subdomain.domain myhostname.UUCP)
dnl #
dnl # our primary name
define(HOSTNAME, myhostname.subdomain.domain)
dnl #
dnl # our uucp name
define(UUCPNAME, myhostname)dnl
dnl #
dnl #-------------------------------------------------------------
dnl #
define(UUCPNODES, |uuname|sort|uniq)dnl # our uucp neighbors
define(BANGIMPLIESUUCP)dnl # make certain that uucp
define(BANGONLYUUCP)dnl # mail is treated correctly
define(RELAY_HOST, my_uucp_neighbor)dnl # our smart relay host
define(RELAY_MAILER, UUCP-A)dnl # we reach moria via uucp
dnl #
dnl #--------------------------------------------------------------------
dnl #
dnl # the various dbm lookup tables
dnl #
define(ALIASES, LIBDIR/aliases)dnl # system aliases
define(DOMAINTABLE, LIBDIR/domaintable)dnl # domainize hosts
define(PATHTABLE, LIBDIR/pathtable)dnl # paths database
define(GENERICFROM, LIBDIR/generics)dnl # generic from addresses
define(MAILERTABLE, LIBDIR/mailertable)dnl # mailers per host or domain
define(UUCPXTABLE, LIBDIR/uucpxtable)dnl # paths to hosts we feed
define(UUCPRELAYS, LIBDIR/uucprelays)dnl # short-circuit paths
dnl #
dnl #--------------------------------------------------------------------
dnl #
dnl # include the 'real' code that makes it all work
dnl # (provided with the source code)
dnl #
include(Sendmail.mc)dnl # REQUIRED ENTRY !!!
dnl #
dnl #------------ END OF SAMPLE SENDMAIL.M4 FILE -------
6.3. Defining a local mailer
Unlike most Unix distributions, Linux does not come with a local mail
delivery agent by default. Now, deliver or procmail is generally
installed, so no complexity will be added to this already very complex
setup. I recommend using the commonly available deliver or procmail
programs, which can be optional packages in a some Linux
distributions.
In order to do so, you need to define a LOCAL_MAILER_DEF in the
sendmail.m4 file that points to a file that looks like:
# -- /usr/local/lib/mail/mailers.linux --
# (local mailers for use on Linux )
Mlocal, P=/usr/bin/deliver, F=SlsmFDMP, S=10, R=25/10, A=deliver $u
Mprog, P=/bin/sh, F=lsDFMeuP, S=10, R=10, A=sh -c $u
There is a also built-in default for deliver in the Sendmail.mc file
that gets included into the sendmail.cf file. To specify it, you would
not use the mailers.linux file but would instead define the following
in your sendmail.m4 file:
dnl --- (in sendmail.m4) ---
define(LOCAL_MAILER_DEF, DELIVER)dnl # mailer for local delivery
Unfortunately, Sendmail.mc assumes deliver is installed in /bin, which
is not the case with Slackware1.1.1 (which installs it in /usr/bin).
In that case you'd need to either fake it with a link or rebuild
deliver from sources so that it resides in /bin. Please note procmail
is generally better than deliver, for example for mail filtering.
6.4. The sendmail+IDA dbm tables
Setting up special behavior for sites or domains is done through a
number of optional dbm tables rather than editing the sendmail.cf file
directly.
Refer to the July-1994 issue of Linux Journal (if you can still find
it :-), to the docs in the sources, or to the sendmail chapter in the
newest version of the Linux DOC Project Networking Administration
Guide which will be available real-soon-now for more details.
· mailertable - defines special behavior for remote hosts or
domains.
· uucpxtable - forces UUCP delivery of mail to hosts that are in
DNS format.
· pathtable - defines UUCP bang-paths to remote hosts or domains.
· uucprelays - short-circuits the pathalias path to well-known
remote hosts.
· genericfrom - converts internal addresses into generic ones
visible to the outside world.
· xaliases - converts generic addresses to/from valid internal
ones.
· decnetxtable - converts RFC-822 addresses to DECnet-style
addresses.
6.5. So which entries are really required?
When not using any of the optional dbm tables, sendmail delivers mail
via the RELAY_HOST and RELAY_MAILER) defined in the sendmail.m4 file
used to generate sendmail.cf. It is easily possible to override this
behavior through entries in the domaintable or uucpxtable.
A generic site that is on Internet and speaks Domain Name Service, or
one that is UUCP-only and forwards all mail via UUCP through a smart
RELAY_HOST, probably does not need any specific table entries at all.
Virtually all systems should set the DEFAULT_HOST and PSEUDONYMS
macros, which define the canonical site name and aliases it is known
by.
If all you have is a relay host and relay mailer, you don't need to
set these defaults since it works automagically. UUCP hosts will
probably also need to set UUCPNAME to their official UUCP name.
They will also probably set RELAY_MAILER and RELAY_HOST which enable
smart-host routing through a mail relay.
The mail transport to be used is defined in RELAY_MAILER and should
usually be UUCP-A for UUCP sites. If your site is SMTP-only and talks
`Domain Name Service', you would change the RELAY_MAILER.
If you're a SLIP site, you might want to take the easy way out and
just forward all outgoing mail to your service provider to do the
right thing with. To do so, you'd want to define ISOLATED_DOMAINS and
VALIDATION_DOMAINS to be your domain, you'd also want to define
RELAY_HOST to be your service provider and RELAY_MAILER to be TCP. Of
course, you want to ask permission before you set any system up as
your general purpose relay.
6.6. Sendmail 8.x
Sendmail 8.7.x from Berkeley was the latest major revision after
sendmail5. It had wonderful built-in support for building under Linux
: just "make linux" and all was set.
You'll probably be best served by grabbing one of the various binary
distributions off of the usual Linux archive sites rather than
fighting things like Berkeley dbm yourself.
There's a nice distribution of sendmail 8.6.12 from Jason Haar -
j.haar at lazerjem.demon.co.uk on sunsite.unc.edu in
/pub/Linux/system/Mail/delivery/sendmail-8.6.12-bin.tgz that has the
source documentation and a very nice quickie description of how to run
sendmail v8 for common configurations.
The bottom line with sendmail v8 is that you want to configure the
bare minimum necessary to get the job done ; the following is an
example that should get you close at least.
6.7. A sample 8.7.x mc file
Much like sendmail+IDA, sendmail v8 uses m4 to process a config file
into a full sendmail.cf that sendmail uses. The following is my
current mc file for my site (ppp to Internet for outgoing mail, uucp
for incoming mail).
dnl divert(-1)
#---------------------------------------------------------------------
#
# this is the .mc file for a linux host that's set up as follows:
#
# - connected to Internet for outbound mail (ppp here)
# - connected via UUCP for incoming mail
# - domainized headers
# - no local mailer (use 'deliver' instead)
# - no DNS running so don't canonicalize outgoing via DNS
# - all non-local outbound mail goes to the RELAY_HOST over smtp
# (we run ppp and let our service provider do the work)
#
# vds 3/31/95
#
#---------------------------------------------------------------------
include(`../m4/cf.m4')
VERSIONID(`linux nodns relays to slip service provider smarthost')dnl
Cwmyhostname.myprimary.domain myhostname.UUCP localhost
OSTYPE(linux)
FEATURE(nodns)dnl
FEATURE(always_add_domain)dnl
FEATURE(redirect)
FEATURE(nocanonify)
dnl MAILER(local)dnl
MAILER(smtp)dnl
MAILER(uucp)dnl
define(`RELAY_HOST', smtp:my.relay.host.domain)
define(`SMART_HOST', smtp:my.relay.host.domain)
define(`UUCP_RELAY', smtp:my.relay.host.domain)
define(`LOCAL_MAILER_PATH', `/bin/deliver')
define(`LOCAL_MAILER_ARGS', `deliver $u')
6.8. Sendmail v8 tidbits
There are a few differences I suppose to the 'IDA bigots' among us.
So far, I've found the following:
Instead of 'runq', you type 'sendmail -q' to run the queue !
6.9. Local Delivery Agents
Unlike most operating systems, Linux did not have mail "built-in" :
you needed a program to deliver the local mail, like "lmail",
"procmail" or "deliver".
However, every recent distribution includes a local mailer now !
Documentation for how to use either for local delivery is in the
sendmail5.67b+IDA1.5 binary release (on sunsite) mentioned above.
7. POP mail
This section also concerns IMAP, not very different from POP.
7.1. History
On a workstation network, mail has always been a problem:
· Either you use "user@computer.foo.com" with problems when
"computer" is down, making your network known to the people
outside, having different addresses for a same person switching to
another computer, ...
· Either you take a mail hub, "mailhost.foo.com" with rules for
rewriting, so every user seems to post from the same address, even
if they are on different computers.
But in that case, how can user read their mail ?
Using a rsh with elm ? :-)
It would overload our mail hub ! One method was forwarding or UUCP,
smtp, etc. but it's too complicated.
Then came POP/IMAP, both with security problems at the beginning, now
fixed using ssh on new versions) : a mail program has sometimes to be
set locally (like qmail, smail or vmail if, for example, you use elm,
but mozilla will avoid that !) however, getting and sending Email is
simpler.
7.2. Getting mail
Here come POP's main drawbacks : the password is sent as a clear text
on the network, and some mail readers just don't know POP : you must
choose a POP-aware mailer, like Pine, Emacs, Netscape, Mutt ...
Password problem can be solved creating a crypted "channel" to have
POP on it or using APOP or RPOP extensions. The mail reader problem
can be solved either by changing mail reader (mozilla is POP ready, as
are Emacs and pine) or by using a POP "mail sucker" with a local mail
program.
Here're some pop programs worth trying :
· gwpop (a Good Way to POP) is very protected since it creates a
crypted "channel" and puts mail directly in the "spool" ; however,
it depends on Perl.
· popclient, simple to use :
For example if your login is john and your password PrettySecret,
you will run :
$ popclient -3 -v mail.acme.net -u john -p "PrettySecret" -k -o JOHN-INET-MAIL
· fetchmail, which is actively supported and incredibly simple to use
: it is configured in ~/.fetchmailrc, so you only need to run
fetchmail when you want to retrive your mail.
Here's my .fetchmailrc :
poll mail.server protocol pop3:
forcecr
password PrettySecret;
Please note forcecr option is needed to use fetchmail with qmail which
strictly respects RFCs.
7.3. Sending mail
For this, you must use smtp-aware mail software, like qmail, smail,
vmail or mozilla (this one does everything : mail reader, POP receive,
smtp send !)
Go to one of the previous sections to install and configure the one
you like best. Then, will you will reach "Testing", try to send some
mail to a local account on the mail hub.
7.4. Reading mail
If your program doesn't do everything itself, you can install elm,
pgp, mush, pine ... many good programs are freely available for linux
platforms !
7.5. Testing
To check your mail server has pop, try :
$ telnet mailhost 110
If it works, you will get something like "OK Pop server (...)
starting" : type "quit" !
To install a ssh crypted "channel", first test your mail server typing
:
$ ssh mailhost date
If you get the date, you should be OK. Please note ssh will not ask
for a password, therefore you must create a ".shosts" file on the mail
server, containing client's name. To test ssh port redirection (which
gwpop uses), type :
$ ssh -n -f -L 12314:localhost:110 mailhost sleep 30
then
$ telnet localhost 12314
Then will you hopefully see mail hub's pop banner. If you don't use
ssh, don't forget to comment out $ssh on gwpop script. To check
whether procmail is running, try "procmail -v"
7.6. Using
Now you can edit gwpop Perl script to check everything is ok, then run
gwpop :
$ gwpop -v your-username
POP password on mailhost: yoursecretpasword
If gwpop "error messages" are normal, the mail from mail hub will be
downloaded to your local machine wherever you told gwpop to put it.
(please test with some mail !).
You can also use gwpop as a daemon :
$ gwpop -d $HOME/tmp your-username
gwpop messages are then sent to syslog and gwpop will run endlessly ;
a "HUP" signal will force gwpop to get your mail.
You can get POP software here used on :
ftp://ftp.pasteur.fr/pub/Network/gwpop
ftp://ftp.informatik.rwth-aachen.de/pub/packages/procmail
http://www.cs.hut.fi/ssh/
8. Mail "user agents"
This section contains information related to "user agents", which
means the software the user sees and uses. This software relies on the
"transport agents" mentioned above. Many other mail "User Agents" are
available now (pine, mush ...) but I haven't found any linux-specific
information to tell on them. Please tell me if I'm missing something !
8.1. Mutt
You should have no problem to compile, install or run mutt ; qmail
users will either get qmail patch or run it with -f flag to read their
local mail folder.
If mutt bothers you with an "unknown terminal error" after a
distribution upgrading, just recompile it.
8.2. Elm
Elm compiles, installs and runs flawlessly under Linux. For more
information, see the elm sources and installation instructions. Elm
and filter need to be mode 2755 (group mail) with /var/spool/mail mode
775 and group mail.
Qmail users will get a patch to use nifty qmail features, or will run
elm with -f flag to point to their local mail folder.
If you use a binary distribution, you'll need to create a
"/usr/local/lib/elm/elm.rc" file to override the compiled-in hostname
and domain information:
· replace "subdomain.domain" with your domain name replace
· "myhostname" with you un-domainized hostname replace
#---------- /usr/local/lib/elm/elm.rc ------------------
#
# this is the unqualified hostname
hostname = myhostname
#
# this is the local domain
hostdomain = subdomain.domain
#
# this is the fully qualified hostname
hostfullname = myhostname.subdomain.domain
#
#--------------------------------------------------------
One thing you want to be aware of is that if you have Elm compiled to
be MIME enabled, you need metamail installed and in your path or Elm
will not be able to read MIME mail you've received. Metamail is
available on thumper.bellcore.com and of course via "archie".
In the "too cool to be true" category, there is a distribution of
Elm-2.4.24 that is "PGP-aware". To try it, grab the file
ftp://ftp.viewlogic.com/pub/elm-2.4pl24pgp3.tar.gz, which is elm2.4.24
with PGP hooks added. You configure and build it the same way you do
normal Elm, which means you probably need to add the patches mentioned
above. For what it's worth, I run it here and like it a lot. Of
course, there must be more recent versions available, including elm-
ME+.
While this item is not Linux-specific, it's perceived (wrongly) to be
a nagging Elm bug nevertheless. We've heard that Elm sometimes fails
with a message that it's unable to malloc() some massive number of
bytes. The identified workaround is to remove the post-processed
global mail aliases (aliases.dir and aliases.pag).
THIS IS NOT A BUG IN ELM, it's an error in configuration of Elm by
whomever you got your binary distribution of Elm from.
Elm has an enhanced and non-compatible, format for aliases ; you need
to ensure that the path Elm uses for aliases is different from the
path sendmail/smail uses. From the volume of reports of this problem,
it's apparent that at least one major distribution 'on the street' has
in the past been misconfigured. (from scot at catzen.gun.de (Scot W.
Stevenson) )
The current metamail package requires csh for some of its scripts.
Failure to have csh (or tcsh) will cause most interesting errors...
8.3. Mailx
If you don't have a local mailx program, save yourself the pain : just
go and grab the mailx kit from Slackware 2.1.0 or later, which has a
nice implementation of mailx5.5. If you're into building from sources,
mailx v5.5 compiles without patching under Linux if you have "pmake"
installed.
If anybody is still using it, I strongly recommend removing the old
"edmail" stuff from SLS1.00 and replacing it with mailx.
8.4. Other user agents
The following also are known to run under Linux. Consult "archie" for
details regarding how to find them...
· mutt - by far better than elm, very easy to use
· pine - from the Univ. of Washington
· metamail - allows MIME support
· mh - yet another way to handle mail
· deliver - file/process mail based on rules
· procmail - file/process mail based on rules
· majordomo - manages e-mail lists
· mserv - provide files-by-mail
9. Acknowledgements
The following people have helped in the assembly of the information
and experience that helped make this document possible:
Steve Robbins, Ian Kluft, Rich Braun, Ian Jackson, Syd Weinstein, Ralf
Sauther, Martin White, Matt Welsh, Ralph Sims, Phil Hughes, Scot
Stevenson, Neil Parker, Stephane Bortzmayer and especially many thanks
to Vince Skahan for his huge contribution.
If I forgot anybody, my apologies : just Email me !
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